The DISCOVERY of the ELEMENTS.
XXI. SUPPLEMENTARY NOTE on the DISCOVERY of PHOSPHORUS* MARY ELVIRA WEEKS The University of Kansas, Lawrence, Kansas
A
LTHOUGH most accounts of the discovery of phorescent form of calcium nitrate which had been phosphorus are based mainly on the writings prepared by distilling a solution of chalk in nitric acid of Kunckel von Lowenstern and record the (2),(3). Brand's "cold fire" interested Kunckel greatly events essentially as they have been described in Part and, when he wrote about it to his friend, Johann I1 of this series of articles,? other early records present Daniel K r d t (or Kraft) of Dresden, the latter also a somewhat different story. In 1902 Hermann Peters, came to Hamburg. They visited Brand and suggested a famous German historian of chemistry and pharmacy, that they might he able to sell his secret to some royal made a thorough study of the autograph letters of personage for a high price. According to Leibniz, Brand, KraiTt, Kunckel, Homherg, G. W. Leibniz, both Kunckel and Krafft learned the secret directly and others which are preserved in the Royal Library from Dr. Brand a t that time (I), (4). a t Hanover, and found that, although the various acThe learned Dr. Krafft soon made the new substance counts differ in many respects, they all agree on one known far beyond the walls of Hamburg as he traveled point: namely, that phosphorus was originally dis- to the Netherlands, to England, and even to darkest covered hy Dr. Hennig Brand of Hamburg. Although America ( " d m mitterniichtlichat Amerika") (4). In most historical records present Dr. Brand as an almost an attempt to sell the secret process, he exhibited the mythical character and do not even mention his cold fire in the court of the Great Elector, Friedrich Christian name, he emerges from these rare old letters Wilhelm of Brandenhurg. On April 24, 1676, a t nine as a real human being. in the evening, all the candles were extinguished while Gottfried Wilhelm Leibniz (164G1716) was person- Dr. Krafft performed before a large assembly a number ally acquainted with Hennig Brand, corresponded with of experiments with the "perpetual fire." However, him regularly for a t least four years, and wrote a history he did not reveal the method by which it had been preof the discovery of phosphorus. According to this pared. great philosopher and mathematician, Brand was living In the following spring Dr. KraiTt went to the court in 1677 a t the Michaelisplatz in Hamburg, in the newer a t Hanover, where G. W. Leibniz was serving as lipart of the city. His wife, Frau Margaretha Brand, brarian and historian under Duke Johann Friedrich, was proud of his attainments, and the dates of her and exhibited two little phials that shone like glowletters show that she lived to enjoy the honors which worms. When Leibniz suggested that a large piece resulted from his epoch-making discovery. A stepson of phosphorus might give enough light to illumine an often assisted the doctor in his experiments, and there entire room, Dr. Krafft told him that this would be were other children as well. Although Dr. Brand was impractical because the process of preparation was something of a spendthrift and borrower, the family too difficult (1). One hundred fifty-seven letters from must have lived comfortably on their income of 1000 K r d t are still preserved in the library a t Hanover. Reichsshalers a year. Visionary and impractical though In July, 1678, Leibniz went to Hamhurg and drew he was, his skill in chemistry won the respect of his up a contract between Duke Johann Friedrich and Dr. contemporaries a t a time when iatrochemistry held the Hennig Brand according to which the latter was to forefront in medical thought. Ambrose Godfrey correspond regularly with Leibniz and keep him inHanckwitz once referred to him as "old honest Brandt formed about new developments regarding the "cold of Hamburg" (15). fire." The Duke's part of the contract consisted in the Wben his alchemical experiments revealed the beauti- promise to pay ten thalers a month, with the stipulaful light-giving element, Rrand called it cold fire ("kaltes tion that sixty thalers, or six months' allowance, would Feuer"), or, affectionately, "mein Feuer." The lumi- be paid in advance for revealing the secret processes nous substance which Kunckel subsequently exhibited ("bei Communicirung der Composition und under bereit in Hamhurg was "Balduin's phosphorus," a phos- habendar Curiositaten") (1). Shortly after this Dr. J. J. Becher went to Hamburg *Illustrations collected by F. B. Dains of The University of and attempted to engage Brand for the Duke of Kansas. 7 J. CHEM.Eouc.. 9, 1 6 2 1 (Jan..1932). Meckleburg-Giistrow. In this, however, he was inter-
cepted by Leibniz, who took Dr. Brand back with him to Hanover and advised Duke Johann Friedrich that it would be best to keep him a t the court or send him to the Harz Mountains until the secret processes had been tested. Leibniz thought that Dr. Brand would be able to prepare a large quantity of phosphorus in the mountains and that he might perhaps find the philosophers' stone. Brand did not go to the Harz, however, hut remained in Hanover for five weeks, preparing a fresh supply of phosphorus outside the city and showing Leibniz the secret process according to the agreement. The latter also prepared a quantity of phosphorus and sent some of i t to the physicist Christian Huygens in Paris, who was studying the nature of light (I), (5). Thus Leibniz was the fourth person to prepare the new element (Brand, Krafft, Kunckel, Leibniz) (1). Brand, however, was highly dissatisfied with the pay he had received, and wrote angry letters to Leibniz claiming that it was insufficient for his traveling expenses and the care of his family a t home. Frau Margaretha Brand also wrote angrily to Leibniz, and her husband berated Krafft for inducing him to place confidence in Leibniz instead of in Dr. Becher. He also accused Krafft of having received one thousand thalers for the phosphorus in England. On December 24, 1678, Dr. Krafft sent this letter to Leibniz, saying, "Since you mention having received an angry letter from him [Brand], I am sending you mine herewith. You may compare them and see which is the prettier" (1). Nevertheless, Leibniz advised the Duke to deal more liberally with Dr. Brand, partly out of sympathy, and partly to prevent him from selling his secrets to others. T h i s tactfulness calmed B r a n d ' s wrath, and in 1679 he planned another trip to Hanover to prepare phosphorus on a large scale and reveal his o t h e r chemical secrets. A weekly salary of ten thalers in addition to board and traveling expenses was agreed upon, and a later letter shows that, on this second A m ~ o s eGODPREY( H m c ~ w r r z ) trip, Brand worked 1660-1741 for Duke Johann German chemist and pharmacist F i d i h two trained by Robert Boyle. Founder of the pharmaceutical firm of Godfrey and Cooke in London. The first person to prepare phosphorus on a commercial scale and export it to all parti of Europe.
months. The last letter from Brand in the Hanover library is dated Au-
gust 23, 1682, but, according to Leibniz, he was still living ten years later (I), (4). Hermann Peters thought that possibly other letters from Brand may still exist in Hamburg or elsewhere. Leibniz communicated Brand's method of making phosphorus to C o u n t Ehrenfried Waltervon Tschirnhaus (1651-1708) in Paris, and sent him a 'pecimen by request. When Tschirnhaus published the BrandLeihniz recipe in
GOTTFRIED W~LHELM LEIBNIZ
16461716
German mathematician, philosdpher, historian, and scientist. Independent discoverer of the differential calculus. He was personally acquainted with Brand and Krafft, and wrote a detailed aCMUnt of the discovery of phosphorus, including biographical sketches of Brand, Krafft, Kunckel, and Becher.
the history of the Royal Academy, c o l b e r t recornmended him f o r membership in the French Academy of Sciences, and on July 22, 1682, he was elected. According to Dr. Peters, this recipe was also published in the fifth edition of Nicolas L6mery's T o u r s de Chimie" in 1683 (1). When Krafft went to England, he exhibited phosphorus in the court of King Charles I1 and showed it to the Honorable Robert Boyle (I), (4), (6). The great English scientist then prepared it by a slightly different method and studied its properties more thoroughly than did any other chemist of the seventeenth century (1). When Wilhelm Homberg defended Kunckel's claim to the re-discovery of phosphorus after theoriginalsecret had been lost to the world, Leibniz strove 'to defend the rights of Dr. Brand and stated emphatically that the real discoverer of phosphorus was still living long after Krafft and Kunckel had made the element known, and that he used to complain bitterly about his false treatment (I). Although Krafft published his recipe in 1679, Brand was still living in 1692 ,and even by 1710 Leibniz had heard no report of his death. A. Godfrey Hanckwitz once paid the following tribute to the great Hamburg chemist:
. .
. as all things have their period so has also the bitalir lucula (scintilla, spark) by approaching age. By (in the case of) this uosophus Brandt, it daily lessened and wore off, till at last in the midst of his best experiments it e'en quite extinguished. His fine stare fire, which through art he produced, remained for his memory longer with us than himself . . . . and shined longer than his finmula uitae, that in time of his best occupation did turn and return to its fiery sphere. His acquaintances and mnfidents would feign (if wishes would have done it) have retarded his decrease to set it farther o f f . . . (15).
preparation, suggesting that the recipe might be worded so obscurely as to be meaningless to others, and assuring him that there would be no danger of any one else opening the letter. He complained because Brand had given some phosphorus to Krafft and the chaplain of the Pest House, and begged him to give no more of it to any one else. Kunckel modified the Brand process a little by adding sand to the urine before distilling. In June, 1676, he told his friend, Caspar Kirchmaier, professor of chemistry a t Wittenberg, about the new process, and the latter published a paper on it. It is not known whether or not Kunckel ever prepared the new element on a large scale, but a t the end of his history of phosphorus he wrote, "However, I am not making i t any more, for much harm can come of it" (Z),( 3 ) . Dr. Hermann Peters concluded from a study of these old letters that Kunckel did not re-discover phosphorus, but merely made a little of i t by Brand's method, and that, even without Kunckel, phosphorus would have remained known to the world through the efforts of Krafft, Leibniz, and Boyle (I). In his article entitled "The Aerial Noctiluca," Robert Boyle mentioned that "the experienced chymist Mr. Daniel Krafft had, in a visit that he purposely made me, shewn me and some of my friends, both his liquid and consistent phosphorus. . ." In return for some information about "uncommonmercuries, . . . he [Krafft], in requital, confest to me a t parting, that at least the principal matter of his phosphorus's was somewhat that belonged to the body of man. ." (6),(19). On September 30, 1680, Boyle's efforts to prepare the luminous element were crowned with success and two weeks later he deposited his recipe with the secretaries of t h e Royal Society, who, however, did n o t open it until after he had died (7). Boyle's assistant, ~ m b i o s e Godfrey Hanckwitz (16601741), was therefore able to develop t h e process on a commercial scale, improve it, and export phosphorus to European scientists (s), (9),(17). cemanhistorian of chemistry. H a n c k witz h a d Author of many articles on Boerhaave, been brought over L?voisier, GeOffroythe Marggraf, Thomas Graham, and Canfrom Germany a t nnzaro. Contributor to "Dm Buch an early age by his der grossnz Chemiker." In 1929 he the Boylc-Hanckwitz recipe for honored master. found phosphorus, after it had been kept He later built fur- secret for more than two centuries.
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In this portrait by George Vertue (1718), the bust of Hanckwitz is shown surrounded by his apparatus. At the left are shown the furnace and receiver used in the manufacture of phosphorus. The molten product was removed with a ladle to the molds in which it was cast into sticks, the entire operation heing carried out under water. Flaming phosphorus and the phoenix, emblem of fire and immortality, figure prominently in the foreground.
According to Leibniz, Brand was not secretive, but, on the contrary, gave over the process too readily to Krafft and Kunckel in return for some little gifts and the promise of larger payments (1). (4). When Kunckel tried out the process a t home, his first attempts were unsuccessful. His complaining letters to Brand brought him no further information, however, for the Hamburg chemist had soon regretted his poor bargain. I n the meantime Kunckel experimented by a trial and error method, and, since he had seen the-process and was familiar with Brand's distillation apparatus, he finally succeeded in correcting his own mistake. He then had the audacity to claim the discovery for himself ( I ) , (4). In alettertoBrand writtenfrom Wittenberg on June 25, 1676, Kunckel asked h i directly for the details of
naces and stills in Maiden Lane, and traveled through the Netherlands, France, Italy, and Germany. He founded a famous pharmaceutical firm in London, and so great was his fame that a letter once came to him safely from Berlin addressed simply, "For Mr. Godfrey, famous Chymist in London" (15). He was known in England simply by the name Ambrose Godfrey, the German surname being reserved for formal occasions. The letters which constitute his correspondence with Sir Hans Sloane from 1721 to 1733 are still preserved in the British Museum ( I S ) ,and in 1858 Joseph Ince wrote an interesting biographical sketch of Hanckwitz based on correspondence, diaries, and notes (15). In spite of all his dangerous experiments with phosphorus, this great disciple of Robert Boyle lived to be an octogenarian. He died on January 15,1741, and was survived by three sons, Boyle, Ambrose, and John Godfrey, all of whom shared their father's interest in science. Hanckwitz kept his recipe for phosphorus a profound secret, and, even in the article which he published in 1733, forty or fifty years after leaving Boyle's laboratory, gave only an obscure description of the process (8), (10). The sons evidently adopted the same policy, for one of them wrote:
to keep it under water. In a second letter written on September 9 of the same year, Dr. Hampe gave Henckel further information about the process. On November 15 he asked Henckel not to divulge the secret to any one else and suggested that they keep each other informed about the experiments with phosphorus (8). Henckel had learned the details of Kunckel's method of preparing it as early as 1731 from Johann Linck, an
As to the phosphorus made of urine called Kunckel's, we have it described by the Honourable Mr. Boyle, Mons. Homberg, and others. But I shall beg to be excused for not discovering the process how I prepare it, or from giving any farther light into its production than what was done by my father, before the Royal Society, in the year 1733 (16).
Yet only two years after publishing this obscure and indefinite description of the process, the aged Hanckwitz allowed Dr. J. H. Hampe, the court physician, to coax him into revealing the secret (8). Not many years ago Dr. Max S ~ e t e of r Berlin found this long-lost reape in an unexpected place. In the published &rrespondence of the famous Counselor of Mines, Johann Friedrich Henckel of Freiberg (1679-1744), there appears a letter from Dr. Hampe written in London on August 29, 1735 ( 8 ) , (11). In reply to Henckel's inquiries regarding Hanckwitz and the secret process, Dr. Hampe wrote that Boyle's famous assistant was still living, but so forgefful because of advanced age that little could be learned from him. Nevertheless, through diligent questioning of the old man, he had succeeded in getting the essential details of the phosphorus recipe which Henckel had requested. Dr. Hampe asked Henckel to write him about any difficulties that might arise in his attempts to make phosphorus, in order that the aged Hanckwitz might be further questioned if necessary. From this letter it appears that "the true key" to the process, which consisted in distilling a mixture of solid and liquid excrement, "was, above all else, that everything be done under water; especially while pouring it into the molds and while cutting it, enough water must always be a t hand" (a), (11). To avoid the necessity of re-distillation, or rectification, Hanckwitz pressed the phosphorus through leather, being careful
Leipzig apothecary who communicated Kunckel's method of preparing phosphorus to J. F. Henckel. The "Golden Lion" nhamacv was in oosi;essionof the Liuck familv for three eenerations. and their museum of natural history and art was known throughout all Germany. From Ferchl's Apotheker-Kalcnder for 1932. ~
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apothecary in Leipzig. In his letter of May 29, 1731, Linck stated that a better method was being used in England by Hanckwitz, but that he did not know the details (S), (11). In 1743 A. S. Marggraf, a student of Henckel, found a much better way of preparing this element from urine (12), (13), (14) and, since the phosphorus business was no longer as profitable as i t had been, he promptly published the process. As Marggraf himself stated, the new method had been suggested by Henckel's state-
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* Reproduced by courtesy of Mr. Arthur Nemayer, Buchdruckerei und Verlag, Mittenwald, Bavaria, Germany.
ment that, when the "calx of l e a d was digested with sal ammoniac, potassium carbonate, and old urine, and then distilled, a good grade of phosphorus could be obtained. According to Mielcke, the microcosmic salt, NaNH4HP044H20, in the urine was converted by heating into sodium metaphosphate, NaP03. In the meantime the potassium carbonate and carbon reduced the lead chloride and lead oxychloride to lead, after which the carbon and lead reduced the sodium metaphosphate to sodium pyrophosphate and phosphorus (12). Dr. -~ . . Speter has also studied the correspondence between Marggraf and Henckel regarding this interesting method of preparing phosphorus.
* * * * It is a pleasure to acknowledge the kind assistance of Dr. Max Speter of Berlin, who graciously contributed a number of important references on the early history of phosphorus. LITERATURE CITED
(1) PETERS,HE-ANN, "Geschichte des Phosphors nach Leibniz und dessen Briefwechsel," Chm-Zlg., 26, 1190-8 (Dec. 13, 1902). (2) KUNCDL, "Vdlstindiges Laboratorium Chymicum," 4th ed.. Rfidigerschen Buchhandlung, Berlin, 1767, pp. sn"""
.,.
(3) DAVIS. T. L., "Kunckel and the early history of phosphorus," J. CHEM.EDUC.,4, 1105-13 (Sept., 1927). (4) . . LEIBNIZ."Geschichte der Erfindung des Phosphors," Crell's Nezred chem. Archiv., 1, 213-8 (3784). (5) "Oeuvres Compl&es de Christian Huygens," vol. 8, Soc. Hollandaise des Sciences, The Hague, 1899, pp. 217, 236. 238. 24&9. 251-2. 25G7. 267: ibid.. -01. 10. 1905.
(6) "The works of the Honourable Robert Boyle." vol. 4, A. Millar, London. 1744, p. 21. (7) ROYLE,"A phosphoru~," Phil. Trans. Abridgment, 5th ed., 3, 3 5 3 4 (1749); Phil. Trans., 17,5834(Jan., 1692). (8) SPETER, "ZUI Geschichte des Urin-Phosphors: Das entdeckte Phosphor Rezept von Boyle-Hanckwitz," ChemZtg., 53, 1005-6 (Dec. 28, 1929). (9) SXITH, E. F., "Forgotten chemists," J. CREM. EDUC.,3, 3 9 4 0 (Jan., 1926). (10) HANCKWITZ,"Some experiments on the phosphorus urinae, . . . with several observations tending to explain the nature of that wonderful chemical production," Phil. Trans.,38,58-70 (17334); Phil. Tranr.Abridgment, ref. (7). 9, 373-9 (1747); Crell's News chem. Archis., 3, 6-14 (1785). (11) "Mineralogische, chymische, und alchemistische Rriefe von reisenden und anderen Gelehrten an den ehemaligcn Chursachsischen Bergrath J. F. Henkel," 3 vols., Waltherische Buchhandlung, Dresden, 179495. (12) BUGGE,"Das Buch der grossen Chemiker." vol. 1, Verlag Chemie Berlin, 1929, pp. 2314. Article on Marggraf by Speter. (13) MARGGF~E, "Vcrschiedene neue Arten, den Hamphosphorus leichter zu verfertigen. und ihn geschwind aus Phlogiston und einem besondern Hmsalze zusammmzuseteen," Crell's Neues chem. Archiu.. 3,30077 (1785). (14) SPETER,"Zur Geschichte des Marggrafschen Urin-Phosphors." Chem.-techn. Rundrchau, 44, 1049-51 (Aug. 13, 1929). (15) INCE,"Ambrose Godfrey Hanckwitz," Pharm. I. [I], I s ? 126-30, 157-62, 215-22 (Aug., Sept., Od.,1858). (16) INCE, .'On the discovery of phosphorus," Pharm. I . [I], 13, 280-2 (Dec., 1853). (17) GORE,G., "On the origin and progress of the phosphorus and match manufactures," Chem. News, 4, 16-8 (July 13, 1861). AND LEE, "Dictionary of national biography," (18) STEPHEN Macmillan and Co., London, 1890, vol. 22, pp. 3W1. Article on Godfrey or Godfrey-Hanckwitz. (19) "Nitrogen and phosphorus: A classic of science," Sn'. News Letter, 22, 1 0 2 3 (Aug. 13. 1932). Reprint of Boyle's "Aerial Nodiluca," ref. (6).
(This article condudes the swim on "The Discovery of the Elements" begun in the January, 1932, issue.)
